SKEY(1)                    OpenBSD Reference Manual                    SKEY(1)

NAME
     skey, otp-md4, otp-md5, otp-sha1, otp-rmd160 - respond to an OTP chal-
     lenge



SYNOPSIS
     skey [-x] [-md4 | -md5 | -sha1 | -rmd160] [-n count] [-p passwd] <se-
          quence#>[/] key

DESCRIPTION
     S/key is a procedure for using one-time passwords to authenticate access
     to computer systems. It uses 64 bits of information transformed by the
     MD4, MD5, SHA1, or RIPEMD-160 algorithms. The user supplies the 64 bits
     in the form of 6 English words that are generated by a secure computer.
     This implementation of s/key is RFC 1938 compliant.

     When skey is invoked as otp-method, skey will use method as the hash
     function where method is currently one of md4, md5, sha1, or rmd160.

     If you misspell your password while running skey, you will get a list of
     passwords that will not work, and no indication of the problem.

     Password sequence numbers count backwards.  You can enter the passwords
     using small letters, even though skey prints them capitalized.

OPTIONS
     -n count
              Prints out count one-time passwords.  The default is to print
              one.

     -p password
              Uses password as the secret password.  Use of this option is
              discouraged as your secret password could be visible in a pro-
              cess listing.

     -x       Causes output to be in hexadecimal instead of ASCII.

     -md4     Selects MD4 as the hash algorithm.

     -md5     Selects MD5 as the hash algorithm.

     -sha1    Selects SHA-1 (NIST Secure Hash Algorithm Revision 1) as the
              hash algorithm.

     -rmd160  Selects RMD-160 (160 bit Ripe Message Digest) as the hash algo-
              rithm.

EXAMPLE
         % skey 99 th91334
         Enter secret password: <your secret password is entered here>
         OMEN US HORN OMIT BACK AHOY
         %

SEE ALSO
     login(1),  skeyinfo(1),  skeyinit(1)

     RFC1938

TRADEMARKS AND PATENTS
     S/Key is a Trademark of Bellcore.

AUTHORS
     Phil Karn, Neil M. Haller, John S. Walden, Scott Chasin

OpenBSD 2.6                    October 28, 1993                              1